vchoi_fork

[svn-r9603] Purpose:
    Bug fix

Description:
    Correct integer overflow situation for computing the size of a dataset.

Solution:
    Rachet one of the dimensions down far enough that the total size of the
dataset's raw data doesn't overflow a 64-bit int.

Platforms tested:
    FreeBSD 4.10 (sleipnir)
    IRIX 6.? (tesla) w/-n32
    Too minor to require h5committest